$\eta_{b}BB^{\ast}$ vertex from QCD sum rules

TL;DR

This paper uses three-point QCD sum rules to evaluate the form factor and coupling constant of the $\\eta_{b}BB^{\ast}$ vertex, considering off-shell contributions from $B$ and $B^{\ast}$ mesons, providing new insights into meson interactions.

Contribution

It introduces a detailed QCD sum rule calculation of the $\\eta_{b}BB^{\ast}$ vertex, accounting for off-shell effects of both mesons, which is a novel approach in this context.

Findings

Form factors differ for $B$ and $B^{\ast}$ off-shell cases.

Coupling constant results are consistent across both cases.

Provides quantitative estimates for the vertex parameters.

Abstract

The form factor and the coupling constant in the $\eta_{b}BB^{\ast}$ vertex are evaluated in the framework of three-point QCD sum rules. The correlation functions responsible for the vertex is evaluated considering contributions of both $B$ and $B^{\ast}$ mesons as off-shell states. The form factors obtained are different for the two cases, whereas the final results of the coupling constant are compatible.